JP2872475B2 - Water supply system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water supply system for a water supply which is provided with a plurality of pumps driven by an inverter in parallel and is directly connected to a water main.

[0002]

BACKGROUND OF THE INVENTION water supply apparatus using a conventional inverter, since the inverter is expensive, taking a backup method shown in FIG 5. That is, when the pump 8 is operated by the inverter drive, the electromagnetic contactors 1 and 3 are first turned on, and the operation is performed by outputting the operation and speed command signals to the inverter INV. Thereafter, when the pump 9 is operated, the electromagnetic contactor 3 is released, the inverter operation signal and the speed command signal are reset, the electromagnetic contactor 4 is turned on, and the inverter operation signal and the speed command signal are output. I do.

[0003] Incidentally, the inverter sometimes trips in order to protect the power supply from fluctuations and overload. In the event that the inverter trips, see JP-A-59-18809.
As described in Japanese Unexamined Patent Publication No. 6, the electromagnetic contactor 2 or 5 of FIG. 15 is turned on, the operation is switched to a commercial power supply, and operation is performed to supply water.

When two pumps are simultaneously operated to increase the water supply amount, for example, when the pumps 9 are operated in parallel while the pumps 8 are being shifted by an inverter, the electromagnetic contactor 5 is operated. When the pump 9 is turned on, the pump 9 is started with a commercial power supply and operates in parallel at a constant speed. Further, when disconnecting the pumps that have been operated in parallel, the constant speed pump that has been followed is stopped. As a prior art relating to this, Japanese Patent Laid-Open Publication No.
No. 93 is disclosed.

[0005]

In the above-mentioned prior art, when the amount of water used is small, such as at night, the pump is temporarily stopped. However, when the pump is stopped, in the example of the constant discharge pressure control method shown in FIG. 16 , the pressure tank 210 is not filled with water because the pressure is usually constant. Therefore, when it is determined that the amount of water used is small and that the control system (not shown) should be stopped, the pressure tank 21
To fill the water 0, NST from NMIN shown in FIG 6
The pump is stopped after increasing the operating speed of the pump until the feed water pressure rises to H4 under the worst conditions. Further, when starting / stopping the second pump to be operated at a constant speed, the parallel start pressure is set to H2 and the parallel stop pressure is set to H1, so that a pressure fluctuation occurs, which may adversely affect the equipment used. .

[0006] In particular, when the water supply device for water supply is directly connected to the main water supply for operation, the above-mentioned conventional technique cannot be applied as it is. This is because it is necessary to minimize pressure fluctuations in the water main when the water supply device is operated. Therefore, it is necessary to further suppress the pressure fluctuation when a plurality of pumps are operated in parallel as compared with the conventional case. In addition, if the pump is operated with a commercial power supply when the inverter trips, it becomes impossible to control the pressure fluctuation to the water main, so that a countermeasure against this is required.

Further, since the water supply device is composed of a large number of devices and components, there is a problem that the installation is troublesome and the handling is difficult.

[0008] The purpose of the present invention is that the inverters provide the liquid supply system for water that can suppress the influence of the water main finished without a commercial power supply to pump even when tripped.

[0009]

[0010]

SUMMARY OF THE INVENTION The object of the present invention is to provide a suction pipe for sucking water from a water main, a first branch pipe and a second branch pipe branched from the suction pipe, and a first branch pipe and a second branch pipe. a water supply pipe connected to the demand side joins the outlet side of the respective tube, the
Detects the pressure of water supplied to the water supply pipe.
Output pressure detection means and speed command for received power from power supply
The spit first inverter and the first electric motor and is driven by electric motor water sucked in through the first branch pipe which is speed control by receiving power from said inverter for converting to output force to the water supply pipe side as speed of the first drive system configured, the power received from the power supply by a pump
A second inverter and a second electric motor and is driven by electric motor water sucked in through the second branch pipe which is speed control by receiving power from said inverter for converting to output power in accordance with degrees command to the water supply pipe side A second drive system constituted by a second pump for discharging, and the pressure detection means
Terminal pressure using water mains pressure based on detected pressure
Control means for outputting the speed command to perform control,
This is achieved by pressurizing the water in the mains and supplying water to the end .

The above object is also achieved by a suction pipe for sucking water from a water main, a first branch pipe and a second branch pipe branched from the suction pipe, and respective outlets of the first branch pipe and the second branch pipe. A water supply pipe that joins the sides and is connected to the demand side, and provided on the water supply pipe
A pressure detecting means for detecting the pressure of the feed water to be supplied to the water supply pipe, terminal pressure constant control of the power received from the power supply using the water main pressure on the basis of the detected pressure of said pressure detecting means
The first inverter and the first electric motor and the water supply pipe side water sucked through driven the first branch pipe by electric motor which is speed control by receiving power from the inverter for converting the power to perform first by pump constructed first drive system and, water main pressure on the basis of the detected pressure of the pressure detecting means receiving electric <br/> force from the power source to spit on
Inverter that converts and outputs power for performing terminal pressure constant control using power and received power from the inverter
In a second motor and a second driving system composed of water sucked through the second branch pipe is driven by electric motor by a second pump for discharging the water supply pipe side to be speed control, water This is achieved by pressurizing the water in the mains and supplying water to the end .

[0012]

[0013]

[0014]

According to the present invention, one of the first drive system and the second drive system is defective.
Even if a failure occurs, backup can be performed by another system driven by the inverter
Therefore, the influence on the water main pressure is suppressed. Also water
Energy saving due to control using main pipe pressure
Is possible and the water mains pressure fluctuates
However, the terminal pressure is controlled to keep the terminal pressure constant according to the fluctuation.
Rapid changes in pressure can be avoided and rapid changes in terminal pressure
Bouncing back to the main pressure can be prevented .

[0015]

EXAMPLES Hereinafter, a description will be given of an embodiment of the present invention with reference to FIGS. 1 1 4. 1 to 12 show a first embodiment of the present invention. Recently, as shown in FIGS. 1 and 2, a water supply device for water supply (hereinafter referred to as a water supply device) has been started to be directly connected to a water supply main line. In this case, since a large number of water supply devices are directly connected to the water main, there is a concern that the influence of the pressure fluctuation due to the start / stop of the pump of each water supply may affect the water main. Therefore, the water supply device used directly connected to the water main needs to have a minimum pressure fluctuation due to the start / stop of the pump, and the water supply device according to the embodiment of the present invention described below has this pressure. A technique for minimizing fluctuations is provided.

FIG. 1 is an overall schematic configuration diagram of a water supply apparatus according to a first embodiment of the present invention. The two pumps 8 and 9 of this water supply device are stainless steel suction pipes directly connected to a water main via a gate valve 202, and
Each is attached to a branch pipe portion branched into two downstream. A check valve 20 is provided downstream of each of the pumps 8 and 9.
6, 207 and gate valves 208, 209 are connected, and the piping is a water supply pipe 213 that is joined downstream of the pipes and guided to the customer. The water supply pipe 213 is connected to a pressure tank (which may be a diaphragm tank) 210 having an air reservoir therein, and a pressure sensor 211 for generating a pressure signal according to the pressure in the water supply pipe 213.

The pumps 8 and 9 are controlled by the control device 214, and include two inverters for controlling the rotational speeds of the motors IM1 and IM2 for driving the pumps 8 and 9, and a microcomputer for controlling these inverters. The control circuit is incorporated in the control device 214.

FIG. 12 is an external view of the water supply device according to the above-described embodiment. This water supply device is housed in a compact package and is configured to be easy to handle.

FIG. 3 is a diagram showing a power circuit portion of the control device shown in FIG. 1, wherein PW is a power supply, 401 is a wiring breaker,
Reference numerals 402a and 403a denote main circuit contacts of respective electromagnetic contactors for the first pump 8 and the second pump 9, respectively.
405 is an inverter for driving and controlling each of the pumps 8 and 9; N1 and N2 are inverters 404 and
406a, 407
“a” is a signal for an operation command of each of the inverters 404 and 405.

FIG. 4 shows a control circuit of the control device shown in FIG. 1.
Is a stabilized power supply composed of a transformer, a diode bridge, a regulator, etc., 509 is a power supply terminal for supplying the power to a microcomputer (hereinafter abbreviated as a microcomputer), 503 is electromagnetic contactors 402 and 403 and a relay 406. , 407 for controlling opening and closing.

When the electromagnetic contactors 402 and 403 are turned on, their contacts, that is, the contacts 402a and 403 shown in FIG.
a closes. Similarly, when the relays 406 and 407 are excited, the contacts 406a and 407a are closed.

510 and 511 are central processing units 51
3 is an interface for outputting, for example, speed commands N1 and N2 to the inverters 404 and 405 in accordance with the command of No. 3, and is constituted by a D / A converter or the like.

As will be described later, as shown in FIG. 5, a switch 518 is used to set a target value for pressure control in a predetermined relationship, for example, H0, H1. Take it into the CPU 513. Similarly, reference numeral 519 denotes a switch for setting a speed point for switching from a predetermined command speed, for example, a shift command to a fixed speed command or vice versa, and is taken into the CPU 513 via the interface 516. Further, reference numeral 520 denotes an interface for taking in the pressure signal of the water supply pipe detected by the pressure sensor 211, which is taken into the CPU 513 via the port 517. The controller 530 is configured as described above.

FIG. 5 is a diagram illustrating the operating characteristics of the pump when the terminal pressure constant control is performed, and the components denoted by the same reference numerals as those in FIG. 18 have the same meaning. Reference numeral 605 denotes a resistance curve of a pipe or the like. Reference numerals 601 to 604 denote operating speeds Nmax, N1, and Nmi, respectively, when the amount of water used changes.
The intersection of the QH performance curve and the resistance curve when imagined as n,...

The operation of the above-described structure will be described with reference to FIG. Now, in FIGS. 1 and 5, the pressure in the water supply pipe 213 (the pressure tank 210 has substantially the same pressure) is higher than H3 (here, the starting pressure), and the pumps 8 and 9 are operated. It is assumed that both are stopped. At this time, it is assumed that the circuit breaker 401 for wiring in FIGS. 3 and 4 is turned on, the switch 501 is closed, the control device operates, and the apparatus is in a standby state. Of course, H0, H1, H
The data of 3, N1, N2, etc.
701 and stored in the memory (701
Steps).

When the water tap at the demand end (not shown) is opened, the water supply pressure drops. This is detected by the pressure sensor 211 (Step 702). When the pressure detected by the pressure sensor 211 is lower than the starting pressure H3, the control device outputs a signal for turning on the electromagnetic contactor 504 and the relay 506 to the interface 503 through the port 515, and outputs the signal to the interface 503. Outputs a speed command signal N1. Thereby, one pump 8 starts.

By this start, the pump 8 is moved to the point 6 in FIG.
Driven at 04. As the usage increases, the resistance curve 60
5, the operation continues along the top, but when the amount of use decreases, the speed is gradually reduced to continue the low speed NMIN operation (step 703).

When this state is continued for a predetermined time, the state shifts to the standby state of the extremely low speed NMIN of 704 steps.
Then, after taking a certain time in step 705, it is checked in step 706 whether the pressure is H0 or less.
When it becomes below, the speed is updated to NMIN (step 707), and the processing is executed again from step 703.

If the state is equal to or higher than H0, a signal for turning on the electromagnetic contactor 403 and the relay 507 is output from the interface 503 from the controller.
An extremely low speed signal (a speed smaller than NMIN) is output to inverter 405 as speed command signal N2. In this state, since the operating characteristic curve of the pump is below the curve 608, the pump does not work and the idling operation is performed, and the feed water pressure is maintained at a predetermined pressure (the pressure on the curve 605). After a certain period of time, a signal is output to stop the pump 8 that has been operating earlier, the pump 8 is stopped, and the pump 9 that is operated later is operated in a low-speed standby operation, and is put on standby.

When the amount of water used increases and the feedwater pressure starts to fall below H0, the pump speed is increased to respond to this. As the usage increases further, the pump speed is further increased. Assuming that the pump currently in operation is the pump 8, when the operating speed of the pump 8 reaches a predetermined speed N1, signals 402, 406, and
510 is output.

Next, the operation at the time of speed increase and vehicle increase will be described with reference to FIG.
This will be described with reference to FIG. 1) The operating speed of the preceding machine increases from Nmin to N1,
In addition, the water supply pressure drops below the specified value Hi (for sure operation, it is better to take a certain period of time and confirm that the pressure is truly below the specified value before proceeding to the next operation.)
Then, while increasing the speed toward 100% N,
Start the follower below Nmin.

2) Thereafter, as the feedwater pressure falls below the specified value, the preceding machine continues to increase in speed, but the following machine follows Nmi.
Maintain n speed. Here, the reason why the follower is set to Nmin is to prevent the feedwater pressure from rising above a specified pressure as a target value.

3) Thus, even if the preceding machine reaches 100% N and the predetermined time has elapsed, the water supply pressure is maintained at the specified value H.
When the state becomes lower than 3, the follower is commanded to increase the speed from Nmin to 100% N so that the feed water pressure becomes the specified value.

Next, the operation at the time of deceleration and the number of platforms will be described. 1) When both pumps reach 100% N, the operation speed of the follower is fixed at 100% N.

2) When the feed water pressure becomes higher than a specified value due to a decrease in the amount of water used, the speed of the preceding machine is increased from 100% N to N
Command to decelerate toward min.

3) Further, when the amount of use decreases, the speed of the preceding machine reaches Nmin, and the feedwater pressure becomes higher than the specified value H4 even after a certain period of time, the speed of the preceding machine is reduced to an extremely low speed. Thereafter, the preceding aircraft is stopped. this is,
This is to eliminate the adverse effect of the inverter due to the transient current during stop.

The above operation will be described in more detail with reference to the flowcharts of FIGS. First, the feed water pressure is detected in step 801 and it is determined whether the feed water pressure is equal to or lower than a specified pressure (step 802). When the pressure is higher than the specified pressure, the deceleration process is started. When the pressure is lower than the specified pressure, the speed of the preceding machine is increased (step 803), and in the next step 804, it is determined whether or not the operating speed of the preceding machine has reached N1. If the operating speed of the preceding machine is equal to or less than N1, the process returns to step 801. If the operating speed of the preceding machine is equal to or more than N1, the process proceeds to the next step 805.
Start at the following speed: Then, maintain this speed.

Next, after performing the waiting time processing of Δt in step 806, the water supply pressure is detected (step 807).
It is determined whether the detected pressure is equal to or less than a specified value (step 80).
8). If not, the process proceeds to step 815, where the operating speed of the preceding machine is detected, and in step 816, it is determined whether the operating speed of the preceding machine has reached the maximum speed Nmax. Nmax
, The speed lock of the following machine is released from this point, the speed control is resumed, and the preceding machine is moved to the maximum speed N.
It is fixed to max (step 818). In this state, since the operating point of the pump is at the point 602 in FIG. 5, no pressure fluctuation occurs. If Nmax has not been reached, the speed of the preceding machine is increased while the speed of the following machine is locked (step 81).
7) Return to step 806.

If it is determined in step 808 that the operating speed is not lower than the specified value, the operating speed of the preceding machine is detected in step 809, and the operating speed is the minimum speed Nmin. It is determined whether or not (step 810). If not more than Nmin, point 604 in FIG.
Since it is in the vicinity, after performing the waiting time processing of Δt in step 811, it is determined whether or not the pressure is equal to or higher than a specified pressure in step 813. When the pressure is equal to or higher than the specified pressure, the process proceeds to step 814 to stop the preceding machine. Then, the speed lock of the follower is released, the process returns to the step 801 and the process is executed again from here. If it is determined in step 810 that it is not Nmin, the preceding machine is decelerated (step 812), and
Return to 06.

After step 818, the process proceeds to step 819, in which a waiting time process of Δt is executed, and then the feedwater pressure is detected (step 820). In the next step 821, it is determined whether or not the detected pressure value is equal to or less than a specified value. judge. If not, the process proceeds to step 822 of FIG. 9A to detect the operating speed of the follower and determine whether or not this operating speed is the minimum speed Nmin (step 823). Minimum speed Nmin
If it has reached, after performing the waiting time processing of Δt in step 825, it is determined in step 826 whether or not the pressure is equal to or higher than the specified pressure H4. If the result of the determination is H4 or more in FIG. 5, the preceding machine is turned off in step 827, the operating speed lock of the following machine is released, and the process returns to step 801 to execute again. If it is determined in step 823 that it has not reached Nmin, deceleration processing is performed in step 824, and the process returns to step 819.

If it is determined in step 821 that the value is equal to or less than the specified value, the process proceeds to step 828 in FIG. 9B, where the operating speed of the follower is detected, and the operating speed becomes the maximum speed Nmax in the determination in step 829. When the speed has reached, the speed is not changed (step 831), and when the speed has not reached the maximum speed Nmax, the speed increasing process is performed (step 830), and the process returns to step 819.

If the pump control is performed as described above,
When the pumps are stopped, the pumps that have been operated earlier can be stopped earlier, so that the operating loads of a plurality of pumps can be equally divided.

FIG. 10A is a diagram showing a state in which the pressure fluctuation when each pump is inverter-controlled in the water supply apparatus according to the above-described embodiment is suppressed. FIG. 10 (b) for comparison is an example in which a pump of the inverter operation and a pump of the rated operation are combined. However, a sudden pressure fluctuation occurs when the pump of the rated operation is operated at the time of switching. Is shown.

In the present embodiment, as shown in FIG. 11, the pressure of the water main can be used as compared with the current system using a water receiving tank, so that the pump pressure can be reduced and energy saving can be achieved. Can be.

[0045] Figure 1 3 is a diagram of a control circuit of the water supply apparatus according to a second embodiment of the present invention. In this embodiment, the speed command signal to the inverter is one point. Now, it is assumed that the amount of water used is small and the pump 8 is operated under the characteristic curve 609 at the extremely low speed Nmin shown in FIG.

In this state, if a state where the amount of used water is small is detected, the operation signal 407 of the inverter 405 for driving the other pump is turned ON, and the same speed command signal N as that of the preceding inverter is output to switch both pumps. Both operate at extremely low speeds. Then, after a certain time, the preceding pump is stopped. Also in this case, since the operation of the pump is switched by lapping, it goes without saying that pressure fluctuation does not occur, and furthermore, since only one speed command signal is required, the control device can be configured at a low cost.

[0047]

[0048]

[0049]

[0050]

[0051] Figure 1 4 is a schematic diagram of a water supply apparatus according to a third embodiment of the present invention. In the present embodiment, a water receiving tank is provided between the water main of the first embodiment and the water supply device,
Other configurations are the same as those of the first embodiment. 1 4,
201 is a receiving tank, 202, 203, 208, 209, 2
12 is a gate valve, 204 and 205 are pumps driven by inverters, 206 and 207 are check valves, 210
Is a pressure tank having an air reservoir therein (may be a diaphragm tank), and 211 is a pressure sensor provided in the water supply pipe 213 and emitting a pressure signal according to the pressure therein.

As described above, the water supply apparatus according to each of the above-described embodiments is configured to be used by directly connecting to the water main, but can be applied to an apparatus having a water receiving tank.

[0053]

According to the present invention, even if an inverter for controlling a pump operating directly connected to a water main is tripped, the other pump can be controlled by an inverter provided for the pump. In addition, even when the inverter trips, the pump does not need to be operated by the commercial power supply, and the fluctuation of the main pipe pressure can be suppressed .

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a water supply device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a water supply system using the water supply device of the present embodiment.

FIG. 3 is a power circuit diagram of the control device shown in FIG. 1;

FIG. 4 is a control circuit diagram of the control device shown in FIG. 1;

FIG. 5 is an operation characteristic diagram when the terminal pressure constant control operation is performed by the water supply device shown in FIG. 1;

FIG. 6 is an operation characteristic diagram showing operations at the time of speed increase and vehicle increase in the first embodiment.

FIG. 7 is a flowchart showing an operation procedure in the first embodiment.

FIG. 8 is a flowchart showing an operation procedure in the first embodiment.

FIG. 9 is a flowchart showing an operation procedure in the first embodiment.

FIG. 10 is a characteristic diagram illustrating a pressure fluctuation suppressing effect in the first embodiment.

FIG. 11 is a diagram showing an energy saving effect in the first embodiment.

FIG. 12 is an external view of a water supply device according to the first embodiment.

FIG. 13 is a power circuit diagram of a water supply device according to a second embodiment of the present invention.

FIG. 14 is a schematic configuration diagram of a water supply device according to a third embodiment of the present invention.

FIG. 15 is a power circuit of a control device in a conventional water supply device.
FIG .

FIG. 16 is an operation characteristic diagram of a conventional water supply device .

[Explanation of symbols]

202, 203: Gate valve, 8, 9, Pump, IM1,
IM2: electric motor, 210: pressure tank, 211: pressure sensor, 401: breaker, 402, 403: electromagnetic contactor,
INV1, INV2: General-purpose inverter, N1, N2: Speed command signal, 406, 407: Inverter operation command signal, 501: Switch, SW1, SW2, SW3: Dip switch, 502: Transformer, 508: Control
503, 510 to 517, an input / output device, 514, a memory, 513, a central processing unit, 504 to 507, a relay.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-86974 (JP, A) JP-A-2-286888 (JP, A) JP-A-57-102586 (JP, A) 136868 (JP, U) Japanese Utility Model Application Sho 58-152577 (JP, U) JP 2-46799 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) F04B 49/06 321 F04B 49/08 311 F04B 15/00

Claims (2)

(57) [Claims] 1. A suction pipe for sucking water from a water main, a first branch pipe and a second branch pipe branched from the suction pipe, and a first branch pipe.
A water supply pipe which joins the outlet side of each of the branch pipe and the second branch pipe and is connected to the demand side; and a water supply pipe provided in the water supply pipe.
A pressure detecting means for detecting the pressure of the feed water supplied, first converting to output force received power according to the speed command from the power supply
The inverter and the first electric motor and is driven by electric motor water sucked in through the first branch pipe which is speed control by receiving power from the inverter constituted by a first pump for discharging the water supply pipe side 1 of the drive system, receiving electricity from the second inverter and said inverter for converting output power according to the speed command to the power received from the power supply
A second drive system constituted by the second pump for discharging the second electric motor and is driven by electric motor water sucked in through the second branch pipe which is velocity controlled by force to the water supply pipe side, the pressure Based on the detection pressure of the detection means
The speed command for performing the terminal pressure constant control using the pipe pressure is
Control means to output the water
Water supply device for water supply that supplies water to the end . 2. A suction pipe for sucking water from a water main, a first branch pipe and a second branch pipe branched from the suction pipe, and the first branch pipe.
A water supply pipe which joins the outlet side of each of the branch pipe and the second branch pipe and is connected to the demand side; and a water supply pipe provided in the water supply pipe.
Pressure detecting means for detecting the pressure of supplied water, and receiving power from a power supply based on the detected pressure of the pressure detecting means.
The first is driven by an electric motor and electric motor the controlled velocity by receiving power from the first inverter and the inverter for converting the power to perform the terminal pressure constant control using the water main pressure the first A first drive system constituted by a first pump for discharging water sucked through a branch pipe to the water supply pipe side, and power received from a power source is used as a water main pressure based on a detection pressure of the pressure detection means . End
It said driven by the second inverter and the second electric motor and the electric motor which is speed control by receiving power from the inverter for converting the power to perform the pressure constant control second
A second drive system configured by a second pump for discharging water sucked through the branch pipe to the water supply pipe side ,
A water supply device for water supply that pressurizes the water in the water main and supplies water to the end .